Hydropneumatic tank float



Dec. 12, 1967 R. J. DAVID HYDROPNEUMATIC TANK FLOAT Filed Sept. 15, 1965 IN VENTOR Robex+ J. Dawd Mg ESRNE Y S United States Patent Oflflce 3,357,591 Patented Dec. 12, 1967 3,357,591 HYDROPNEUMATIC TANK FLOAT Robert J. David, Orange, Conn., assignor to The American Granby Company, Milford, Conn. Filed Sept. 15, 1965, Ser. No. 487,550 8 Claims. (Cl. 22026) ABSTRACT OF THE DISCLOSURE A hypdropneumatic tank float which comprises a continuous flexible flotation ring between complementary discs of flexible material where the flexible material is fused together along concentric radially spaced apart lines outwardly of the flotation ring with the outermost of said lines defining an integral rim for the float and the innermost defining an envelope for the ring.

This invention relates to fluid pressure systems, and more particularly relates to an improved floating diaphragm for use in fluid distribution or hydropneumatic tanks.

In domestic water systems it is common practice to provide a hydropneumatic tank in the line from a well or other water source which stores a predetermined quantity of water under pressure available for immediate use upon demand. It has become the practice to provide a floating diaphragm on the surface of the water in the tank to provide an effective seal over the surface of the water and prevent absorption of the air in the tank by the water therein, while at the same time allowing a uniform pressure to be exerted on the surface of the water in the tank.

This invention provides a new and improved diaphragm for the purposes described which is so constructed and arranged as to be easily foldable for insertion through a narrow opening in an existing hydropneumatic tank. The diaphragm is of simple and economical construction and manufactured in a new and improved manner. The construction and method of construction of the diaphragm is such that a flotation ring positioned therein is always disposed essentially concentrically within an envelope formed by a pair of flexible disc shaped members. The flotation ring is positioned in the envelope, and the envelope defined by integrally joining the two disc-like members together along concentric circular lines or paths. The two concentric lines of seal define an annular flange adapted to engage the inside wall of a hydropneumatic tank. Addition ally, the innermost line of seal is so positioned and arranged as to concentrically locate and position the flotation ring. The flotation ring is made in a continuous circle of hollow flexible tubing. The tubing is selected to be of a material which has sutficient properties of elasticity to allow the entire ring to be bent double and inserted through a narrow opening in a hydropneumatic tank.

Accordingly, an object of this invention is to provide a new and improved diaphragm construction for a hydropneumatic tank and a new and improved method of making the same.

Another object of this invention is to provide a floating diaphragm of the type described having a one-piece continuous flotation ring which is positioned and located with an envelope comprising two flexible disc-like members by a seal between the members which also aids in defining a flexible flange on the diaphragm.

A further object of this invention is to provide a new and improved method of making a diaphragm of the type described.

The features of the invention which are believed to be novel are set forth with particularity and distinctly claimed in the concluding portion of this specification.

The invention, however, both as to its organization, operation and method of fabrication, together with further objects and advantages thereof, may best be appreciated by reference to the following detailed description taken in conjunction with the drawings, in which:

FIG. 1 is a plan view of a diaphragm embodying the invention which is cut away in part to facilitate illustration thereof;

FIG. 2 is a view seen in the plane of line 22 of FIG. 1;

FIG. 3 is an elevation in half section of a hydropneumatic tank utilizing a diaphragm embodying the invention;

FIG. 4 is a sectional view of apparatus utilized in manufacting a diaphragm embodying the invention illustrating the method of making a diaphragm; and

FIG. 5 is a view in perspective of the diaphragm of FIGS. 1 and 2 in a folded position arranged for insertion into the tank illustrated in FIG. 3.

A diaphragm embodying the invention is generally indicated by the reference numeral 10 and comprises complementary disc-shaped members 11 and 12 of a flexible sheet material, preferably polyvinyl chloride, which are sealed to form an envelope about a flotation ring 13.

In accordance with one aspect of the invention, flotation ring 13 is formed as a continuous ring of constant cross-section about an axis generally indicated by the reference numeral 14. Ring 13 is an ethylene-vinyl acetate copolymer which is extruded into a hollow tube of predetermined length which then is curved about the axis 14 and has its ends joined together, as by welding. This may be accomplished by placing the ends to be joined on opposite sides of a heated blade having suflicient heat to fuse the ends thereof, and then withdrawing the blade while joining the heated end portions which fuse together to provide a continuous integral tube. Thus material has a low temperature flexibility which makes it superior to many rubber products now in use and other elastomeric materials. The flotation ring thus formed has the characteristics of rigidity because of its tubular structure. However, it has sufiicient flexibility and elastic memory to allow it to be bent double at generally diametrically opposed points and it will immediately snap back to its unstressed condition. This material is available from the U.S.I. Chemicals Division of National Distillers & Chemical Corp, New York, NY. under the trademark Ultrathene UE-631.

In further construction of the diaphragm It the ring 13 is placed between two complementary disc-shaped sheets of a suitable flexible material such as polyvinyl chloride. The sheets are then integrally joined along concentric lines 15 and 16. Preferably this assembly is then placed in a press which holds suitable sealing dies and pressure is applied along the lines of seal 15 and 16 through the use of brass rule dies formed into concentric circles. These dies, in eflect, form electrodes which are placed on either side of the lines of seal 15 and 16 and excited at a high frequency on the order of approximately twenty-six megacycles. This, in effect, is a form of dielectric heating which fuses or welds the discs 11 and 12 together along the lines 15 and 16. Along the lines 15 and 16 the discs 11 and 12 are integrally joined. The lines of seal 15 and 16 define an annular flexible flange 17 extending outwardly of flotation ring 13. The overall diameter of diaphragm 10 is so selected that the integrally formed rim or periphery of flange 17 abuts the inner wall of tank 18 as it floats on top of the water therein. Additionally, the flexibility of flange 17 allows it to easily ride over any internal projections that may extend inwardly within the tank, and not allow the flotation properties of the diaphragm to be affected by any discrepancies or any nonuniformities in the inside diameter of the tank.

It will be understood that the hydropneumatic tanks are manufactured to certain tolerances and the diameter may not be strictly constant throughout its length. For example, there may be a small taper along the length of the tank. Such taper would be very small. However, the flexibility of the flange and the diameter of flotation ring 13 with respect to the diameter of the tank into which the dia hragm is to be inserted is so selected that the difference in diameters is substantially greater than any diametric manufacturing tolerances.

This sealing technique and structure insures that the flotation ring 13 is concentrically sealed Within a Watertight envelope comprised by the members 11 and 12. The circular seal positions the ring 13 within the envelope and holds it in such position to prevent any shifting thereof which might occur during a turbulent condition within tank 18. The seal 16 provides a fused or welded rim which is impervious to separation as might be the case if the discs were merely bonded together.

With the ring 13 and seals 15 and 16 all essentially concentric, there can be no shifting of ring 13 in the envelope and the flange 17 remains of constant width throughout its length. Therefore, the float will remain stable regardless of any turbulence that may be produced in tank 18 due to pumping of water therein, draw down, etc. Additionally, the float cover essentially all of the water in the tank at all times and, therefore, the pressure exerted on the water is uniform, and absorption of the air into the water is essentially eliminated.

FIG. 4 is illustrative of one die arrangement which may be utilized to effect the heat seals. In the structure of FIG. 4 an upper die member has two brass-rule dies 20 and 21 concentrically arranged on an aluminum platen 22 and a lower die 23 is similarly constructed together with a support 24 for the disc and ring members.

FIG. 5 illustrates the manner in which the diaphragm 10 may be folded and also deformed to allow insertion through the opening 25 of tank 18. It is important to note that the portions of the discs 11 and 12 within the bounds of ring 13 are not bonded together and may, therefore, slide relative to one another when the diaphragm is bent and deformed as shown in FIG. 5.

In practice, the outside diameter of ring 13 is so chosen with respect to the overall diameter of the diaphragm that the flange measures approximately one inch.

It may thus be seen that the objects of the invention set forth above as well as those made apparent from the preceding description are efliciently attained. Inasmuch as other embodiments of the invention as well as modifications to the disclosed embodiment thereof may occur to others, the appended claims are intended to cover all embodiments of the invention which do not depart from the spirit and scope thereof.

What is claimed is:

1. A flexible floating diaphragm for a hydropneumatic tank comprising a flotation ring, a pair of complementary discs of flexible sheet material on either side of said ring coaxial therewith, said discs being fused together along concentric radially spaced apart lines outwardly of said ring, the outermost of said lines defining an integral rim and the innermost defining an envelope for said ring, said lines defining a flexible flange extending radially outwardly of said ring.

2. A flexible floating diaphragm for a hydropneumatic tank comprising a flexible flotation ring capable of being folded 180 upon itself formed of a length of tubing of ethylene-vinyl acetate copolymers having its ends integrally joined together to form said ring, a pair of complementary discs of flexible sheet material on either side of said ring coaxial therewith, said discs being fused together along concentric radially spaced apart lines outwardly of said ring, the outermost of said lines defining an integral rim and the innermost defining an envelope for said ring, said lines defining a flexible flange extending radially outwardly of said ring.

3. The method of making a flexible floating diaphragm for a hydropneumatic tank including a flotation ring sealed within an envelope having a flexible peripheral flange comprising the steps of providing a flotation ring, positioning a pair of complementary discs of flexible sheet material on either side of said ring coaxial therewith and fusing said discs together along concentric radially spaced apart lines outwardly of said ring, the outermost of said lines defining an integral rim and the innermost defining an envelope for said ring, said lines defining a flexible flange extending radially outwardly of said ring.

4. A flexible floating diaphragm for a hydropneumatic tank comprising a flotation ring, said flotation ring com prising a continuous integral length of highly resilient tubular material foldable up to upon itself and able to snap back to an unstressed planar condition, a pair of complementary discs of flexible sheet material on either side of said ring coaxial therewith, said discs being fused together along concentric radially spaced apart lines outwardly of said ring, the outermost of said lines defining an integral rim and the innermost defining an envelope for said ring, said lines defining a flexible flange extending radially outwardly of said ring.

5. A flexible floating diaphragm for a hydropneumatic tank comprising a flotation ring, said flotation ring comprising a continuous integral length of highly resilient tubular material foldable up to 180 upon itself and able to snap back to an unstressed planar condition, a pair of complementary discs of flexible sheet material on either side of said ring coaxial therewith, said discs being fused together along concentric radially spaced apart lines outwardly of said ring, said discs being thus sealed together outside of said ring to define an envelope for said ring and a flexible flange thereabout.

6. A diaphragm adapted to be inserted in a hydropneumatic tank having a predetermined substantially uniform diameter along the length thereof comprising a continuous tubular flotation ring adapted to be folded substantially 180, said ring comprising a length of tubing shaped into a ring and having its ends intergrally joined, a pair of flat disc shaped members of flexible material having a greater diameter than said ring disposed on either side of said ring, the edges of said disc members being fused to each other to provide a continuous integral bond between said members and an integral rim for said diaphragm, said members being fused to each other along a continuous circular line concentric with said rim and disposed radially inwardly of said rim to define an envelope for said ring.

7. The diaphragm of claim 6 wherein said flotation ring is an ethylene-vinyl acetate copolymer.

8. A diaphragm adapted to be inserted in a hydropneumatic tank having a predetermined substantially uniform diameter along the length thereof, comprising a tubular continuous flotation ring comprising a length of highly resilient tubing shaped into a ring and having its ends joined, a pair of flat disc shaped members of flexible material having a greater diameter than said ring disposed on either side of said ring, the edges of said members being heat sealed to each other to provide a continuous bond at the rims thereof, said members being heat sealed to each other along a second continuous circular line concentric with the axis of said ring, said second circular seal concentrically locating said ring within said circular envelope and defining with the sealed rim thereof an annular flexible flange of essentially the same diameter as the inside of the tank.

References Cited UNITED STATES PATENTS 8/1962 Wade et al. 220-26 12/1964 Anderson 220-26 

1. A FLEXIBLE FLOATING DIAPHRAGM FOR A HYDROPNEUMATIC TANK COMPRISING A FLOTATION RING, A PAIR OF COMPLEMENTARY DISCS OF FLEXIBLE SHEET MATERIAL ON EITHER SIDE OF SAID RING COAXIAL THEREWITH, SAID DISCS BEING FUSED TOGETHER ALONG CONCENTRIC RADIALLY SPACED APART LINES OUTWARDLY OF SAID RING, THE OUTERMOST OF SAID LINES DEFINING AN INTEGRAL RIM AND THE INNERMOST DEFINING AND ENVELOPE FOR SAID RING, SAID LINES DEFINING A FLEXIBLE FLANGE EXTENDING RADIALLY OUTWARDLY OF SAID RING. 